Genetics and orofacial clefts: a clinical perspective

Prenatal exposure to antibiotics and the risk of orofacial clefts: a protocol for a systematic review and meta-analysis

INTRODUCTION

Orofacial clefts (OFCs), including cleft lip, cleft palate and combined cleft lip and palate, are among the most common craniofacial malformations in newborns and present significant healthcare challenges. Emerging evidence has raised concerns regarding the potential impact of prenatal exposure to antibiotics on fetal development. Antibiotics prescribed during pregnancy-particularly those that cross the placental barrier-may pose teratogenic risks. Previous studies investigating the association between prenatal antibiotic exposure and the risk of OFCs have yielded inconsistent results. However, no studies have yet attempted to summarise this evidence, highlighting the need for a comprehensive evaluation. This report describes a systematic review and meta-analysis protocol to retrospectively analyse the relationship between prenatal antibiotic exposure and the risk of developing OFCs, focusing on the role of antibiotic type and timing of exposure. The results of such a review will hopefully provide a comprehensive synthesis of the available evidence, helping to inform clinical practice and guide patient counselling regarding the use of antibiotics during pregnancy.

METHODS AND ANALYSIS

The planned systematic review and meta-analysis will adhere to the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols guidelines to ensure a comprehensive and systematic approach to summarising the available evidence on the topic. This study will include longitudinal cohort studies, case-control studies, and interventional trials that investigate the association between prenatal antibiotic exposure and OFCs. The search strategy will cover major databases, including CINAHL, Cochrane Library, ClinicalTrials.gov, EMBASE, PubMed, Scopus and Web of Science, using tailored search terms. A team of independent assessors will screen article titles, abstracts and full texts. Any discrepancies will be resolved through discussions. Quality assessment will use the Newcastle-Ottawa Scale and Grading of Recommendations Assessment, Development and Evaluation criteria. Data extraction will focus on the study characteristics, participant details, exposure specifics and outcome measures. A random-effects meta-analysis will aggregate summary effect sizes, and heterogeneity will be assessed using I2 and Q statistics.

ETHICS AND DISSEMINATION

Ethical approval is not required for this systematic review, as it relies on already published data. The findings will be disseminated through peer-reviewed journals and conference presentations, providing critical insights into clinical practice and public health policies regarding antibiotic use during pregnancy.

PROSPERO REGISTRATION NUMBER

CRD42024565064.

Congenital diaphragmatic hernia and cleft lip and palate: looking for a common genetic etiology

PURPOSE

Congenital diaphragmatic hernia (CDH) and cleft lip and/or palate (CL/P) are inborn closure defects. Genetic factors in and outcomes for patients with both anomalies (CDH+CL/P) remain unclear. We aimed to investigate associated genetic aberrations, prevalence of, and outcomes for, CDH+CL/P.

METHODS

Data from Congenital Diaphragmatic Hernia Study Group (CDHSG) registry were collected. CL/P prevalence in CDH patients was determined. Genetic abnormalities and additional malformations in CDH+CL/P were explored. Patient characteristics and outcomes were compared between CDH+CL/P and isolated CDH (CDH-) using Fisher's Exact Test for categorical, and t-test or Mann-Whitney U-test for continuous, data. p < 0.05 was considered statistically significant.

RESULTS

Genetic anomalies in CDH+CL/P included trisomy 13, 8p23.1 deletion, and Wolf-Hirschhorn syndrome (4p16.3 deletion). CL/P prevalence in CDH was 0.7%. CDH+CL/P had lower survival rates than CDH-, a nearly fourfold risk of death within 7 days, were less supported with extracorporeal life support (ECLS), had higher non-repair rates, and survivors had longer length of hospital stay.

CONCLUSION

Genetic anomalies, e.g. trisomy 13, 8p23.1 deletion, and Wolf-Hirschhorn syndrome, are seen in patients with the combination of CDH and orofacial clefts. CL/P in CDH patients is rare and associated with poorer outcomes compared to CDH-, influenced by goals of care decision-making.

A comprehensive consolidation of data on the relationship between IRF6 polymorphisms and non-syndromic cleft lip/palate susceptibility: From 79 case-control studies

BACKGROUND

Non-syndromic cleft lip with or without cleft palate (NSCL/P) is a prevalent craniofacial birth defect on a global scale. A number of candidate genes have been identified as having an impact on NSCL/P. However, the association between interferon regulatory factor 6 (IRF6) polymorphisms and NSCL/P has yielded inconsistent results, prompting the need for a meta-analysis to obtain more accurate estimates.

METHODS

We conducted a thorough screening of all relevant articles published up until November 15, 2023, in online bibliographic databases. The statistical analysis of the collected data was performed using the Comprehensive Meta-Analysis (Version 4.0) software.

RESULTS

A total of 79 case-control studies, comprising 14,003 cases and 19,905 controls, were included in our analysis. The combined data indicated that the IRF6 rs642961 and rs2235371 polymorphisms were associated with an increased risk of NSCL/P in the overall population. However, no significant association was found between the rs2013162 and rs2235375 polymorphisms and the risk of NSCL/P in the overall population. Furthermore, subgroup analyses revealed significant correlations between the IRF6 rs642961, rs2235371, and rs2235375 polymorphisms and the risk of NSCL/P based on ethnic background and country of origin. Nevertheless, the rs2013162 polymorphism plays a protective role in Caucasians and mixed populations.

CONCLUSIONS

Our collective data indicates a significant association between the rs642961 and rs2235371 polymorphisms and the risk of NSCL/P in the overall population. The rs2235375 polymorphism could influence the susceptibility to NSCL/P based on ethnic background. Meanwhile, the rs2013162 polymorphism provides protective effects in Caucasian, mixed populations, and the Brazilian population.

The prevalence of orofacial clefts in Qatar : a cross-sectional nationwide study

BACKGROUND

Cleft lip and palate are congenital craniofacial anomalies that significantly impact individuals and their families, both medically and psychosocially. The Qatari population has unique characteristics that are suggestive of a high prevalence of congenital anomalies: high consanguinity rate, large family size, advanced paternal age and high prevalence of certain genetic disorders. The lack of existing data concerning the epidemiology of cleft lip and/or palate in Qatar warrants a descriptive study addressing this topic.

METHODS

A retrospective nationwide hospital-based cross-sectional study conducted to determine the prevalence of orofacial clefts in Qatar from 2016 to 2021. Data were extracted from the corporation's Cerner database and electronic health records. Information concerning the cleft's characteristics, type, affected side, patient's gender, presence of associated syndromes, nationality, and maternal age were collected.

RESULTS

Out of the 147,727 live births, 148 had an orofacial cleft. The prevalence of cleft lip and/or palate was determined to be 1 per 1000 livebirths (95% CI: 0.85, 1.18). The prevalence of cleft lip was 0.18 (95% CI: 0.12, 0.27), cleft palate 0.39 (95% CI: 0.30, 0.51), and cleft lip and palate 0.43 (95% CI: 0.33, 0.55). Qataris had a prevalence of CL 0.25, CP 0.40, and CLP 0.56, compared to 0.16, 0.39, 0.39 for non-Qataris (p-value 0.186). Unilateral clefts predominated over bilateral (74.4% and 25.6%, respectively). Among the unilateral cases, 70.2% occurred on the left side. Most cases were isolated clefts, with only 10.2% having associated syndromes.

CONCLUSIONS

The prevalence of orofacial clefts in Qatar is consistent with the globally reported prevalence. Most cases were unilateral and on the left side. Associated syndromes were infrequent and more common with cleft palate alone. Intriguing patterns were revealed between Qatari nationals and non-Qatari residents, with specific subtypes of orofacial clefts showing higher prevalence among nationals.

Parents and Provider Perspectives on the Return of Genomic Findings for Cleft Families in Africa

BACKGROUND

Inadequate knowledge among health care providers (HCPs) and parents of affected children limits the understanding and utility of secondary genetic findings (SFs) in under-represented populations in genomics research. SFs arise from deep DNA sequencing done for research or diagnostic purposes and may burden patients and their families despite their potential health importance. This study aims to evaluate the perspective of both groups regarding SFs and their choices in the return of results from genetic testing in the context of orofacial clefts.

METHODS

Using an online survey, we evaluated the experiences of 252 HCPs and 197 parents across participating cleft clinics in Ghana and Nigeria toward the return of SFs across several domains.

RESULTS

Only 1.6% of the HCPs felt they had an expert understanding of when and how to incorporate genomic medicine into practice, while 50.0% agreed that all SFs should be returned to patients. About 95.4% of parents were willing to receive all the information from genetic testing (including SFs), while the majority cited physicians as their primary information source (64%).

CONCLUSIONS

Overall, parents and providers were aware that genetic testing could help in the clinical management of diseases. However, they cited a lack of knowledge about genomic medicine, uncertain clinical utility, and lack of available learning resources as barriers. The knowledge gained from this study will assist with developing guidelines and policies to guide providers on the return of SFs in sub-Saharan Africa and across the continent.

E-cadherin variants associated with oral facial clefts trigger aberrant cell motility in a REG1A-dependent manner

BACKGROUND

Germline mutations of E-cadherin contribute to hereditary diffuse gastric cancer (HDGC) and congenital malformations, such as oral facial clefts (OFC). However, the molecular mechanisms through which E-cadherin loss-of-function triggers distinct clinical outcomes remain unknown. We postulate that E-cadherin-mediated disorders result from abnormal interactions with the extracellular matrix and consequent aberrant intracellular signalling, affecting the coordination of cell migration.

METHODS

Herein, we developed in vivo and in vitro models of E-cadherin mutants associated with either OFC or HDGC. Using a Drosophila approach, we addressed the impact of the different variants in cell morphology and migration ability. By combining gap closure migration assays and time-lapse microscopy, we further investigated the migration pattern of cells expressing OFC or HDGC variants. The adhesion profile of the variants was evaluated using high-throughput ECM arrays, whereas RNA sequencing technology was explored for identification of genes involved in aberrant cell motility.

RESULTS

We have demonstrated that cells expressing OFC variants exhibit an excessive motility performance and irregular leading edges, which prevent the coordinated movement of the epithelial monolayer. Importantly, we found that OFC variants promote cell adhesion to a wider variety of extracellular matrices than HDGC variants, suggesting higher plasticity in response to different microenvironments. We unveiled a distinct transcriptomic profile in the OFC setting and pinpointed REG1A as a putative regulator of this outcome. Consistent with this, specific RNAi-mediated inhibition of REG1A shifted the migration pattern of OFC expressing cells, leading to slower wound closure with coordinated leading edges.

CONCLUSIONS

We provide evidence that E-cadherin variants associated with OFC activate aberrant signalling pathways that support dynamic rearrangements of cells towards improved adaptability to the microenvironment. This proficiency results in abnormal tissue shaping and movement, possibly underlying the development of orofacial malformations.